1. I am using Thunderbird 52 for connecting with my local email server.
2. The server's openssl module has support of "ECDHE-RSA-AES256-GCM-SHA384" cipher.
3. In thunderbird config editor i have set TB to only send the above mentioned ciphersuite because currently the TB connects with "ECDHE-RSA-AES128-GCM-SHA256" ciphersuite.
4. Now, when I try to connect with ECDHE-RSA-AES256-GCM-SHA384 to my email server. Error comes in.
5. The Debugging mode shows the error to be:
An error occurred during a connection to
192.168.15.100:465.
Bulk data encryption algorithm failed in selected cipher suite.
Error code: <a id="errorCode" title="SSL_ERROR_ENCRYPTION_FAILURE">SSL_ERROR_ENCRYPTION_FAILURE</a>
6. The wireshark shows that TB sends this cipher and server accepts the cipher but then immediately the host system (thunderbird app) sends the FIN packet to terminate the connection.
What can be the issue ?
ps: I have requirement of using AES256GCM-SHA384.